comments on attribute.xsd

[Peter McCartney]

There is meaning to the classification accuracy of nominal and ordinal
values.

i think standard deviation of the average of values is a really a statement
about accuracy not precision. precision is used to indicate when the
miminmum value distinction being reported is not in integrals of the units -
that is, measuring meters to the nearest tenth, or an instrument that
returns degrees, but only in intervals of 5 degrees. its a qualifier to
units in my opinion. in the first case, i could have reported the units as
decimeters with a precision of 1. in the second case, i dont have a unit
definition for 5 degrees, so the best i can do is say its in degrees in
increments of 5.

-----Original Message-----
From: Tim Bergsma [mailto:tbergsma at kbs.msu.edu]
Sent: Thursday, October 31, 2002 10:13 AM
To: Eml-Dev (E-mail)
Subject: comments on attribute.xsd


Hi.

I just read thru eml-attribute.xsd.  

Typos:
canbe
which specify ordered...  (specifies?)
domain violoations
character (in the context of missingValueCode, perhaps character(s))
thatthe

Comments:
It looks like all attributes have accuracy, regardless of scale. 
However, only interval and ratio scales have precision.  That's okay
with me, if there is meaning to the accuracy of categorical values.

However, precision needs work.  We agreed that precision is a
statistical thing, and is pretty useless without a descriptive
interpretation.  Accuracy has a place to describe the test that produced
the value, but precision doesn't have anything equivalent.  This is
bad.  Consider, for example, that better precisions usually have lower
numeric values!  There's got to be a way to describe what the precision
means.  (Often it is the standard deviation of repeated measurements.)

Tim.
-- 
Tim Bergsma
LTER Information Manager
W.K. Kellogg Biological Station
Michigan State University
Hickory Corners, MI   49060
616/671-2337
tbergsma at kbs.msu.edu
http://lter.kbs.msu.edu
_______________________________________________
eml-dev mailing list
eml-dev at ecoinformatics.org
http://www.ecoinformatics.org/mailman/listinfo/eml-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mercury.nceas.ucsb.edu/ecoinformatics/pipermail/eml-dev/attachments/20021031/cb6fdf90/attachment.htm